package com.libraries.view.refreshload;

import java.util.Timer;
import java.util.TimerTask;

import android.annotation.SuppressLint;
import android.content.Context;
import android.os.Handler;
import android.os.Message;
import android.util.AttributeSet;
import android.util.Log;
import android.view.MotionEvent;
import android.view.View;
import android.view.ViewGroup;
import android.view.animation.AnimationUtils;
import android.view.animation.LinearInterpolator;
import android.view.animation.RotateAnimation;
import android.webkit.WebView;
import android.widget.AbsListView;
import android.widget.RelativeLayout;
import android.widget.ScrollView;
import android.widget.TextView;

import com.libraries.helper.Logger;
import com.libraries.view.refreshload.listener.IPullToRefreshLoadListener;
import com.example.libraries.R;

/**
 * 自定义的布局，用来管理三个子控件，其中一个是下拉头，一个是包含内容的pullableView， 还有一个上拉头
 * 
 */
@SuppressLint("NewApi")
public class PullToRefreshLoadLayout extends RelativeLayout {
	// 初始状态
	public static final int INIT = 0;
	// 释放刷新
	public static final int RELEASE_TO_REFRESH = 1;
	// 正在刷新
	public static final int REFRESHING = 2;
	// 释放加载
	public static final int RELEASE_TO_LOAD = 3;
	// 正在加载
	public static final int LOADING = 4;
	// 操作完毕
	public static final int DONE = 5;
	// 当前状态
	private int currState = INIT;
	// 刷新回调接口
	private IPullToRefreshLoadListener mListener;
	// 刷新成功
	public static final int SUCCEED = 0;
	// 刷新失败
	public static final int FAILED = 1;
	// 按下Y坐标，上一个事件点Y坐标
	private float downY, lastY;

	// 下拉的距离。注意：pullDownY和pullUpY不可能同时不为0
	public float pullDownY = 0;
	// 上拉的距离
	private float pullUpY = 0;

	// 释放刷新的距离
	private float refreshDist = 200;
	// 释放加载的距离
	private float loadMoreDist = 200;

	private RefreshLoadTimer refreshLoadTimer;
	// 回滚速度
	public float MOVE_SPEED = 8;
	// 第一次执行布局
	private boolean isLayout = false;
	// 在刷新过程中滑动操作
	private boolean isTouch = false;
	// 手指滑动距离与下拉头的滑动距离比，中间会随正切函数变化
	private float radio = 2;

	// 下拉箭头的转180°动画
	private RotateAnimation rotateAnimation;
	// 均匀旋转动画
	private RotateAnimation refreshingAnimation;

	// 下拉头
	private View refreshView;
	// 下拉的箭头
	private View pullView;
	// 正在刷新的图标
	private View refreshingView;
	// 刷新结果图标
	private View refreshStateImageView;
	// 刷新结果：成功或失败
	private TextView refreshStateTextView;

	// 上拉头
	private View loadMoreView;
	// 上拉的箭头
	private View pullUpView;
	// 正在加载的图标
	private View loadingView;
	// 加载结果图标
	private View loadStateImageView;
	// 加载结果：成功或失败
	private TextView loadStateTextView;

	// 实现了Pullable接口的View
	private View pullableView;
	// 过滤多点触碰
	private int mEvents;
	// 这两个变量用来控制pull的方向，如果不加控制，当情况满足可上拉又可下拉时没法下拉
	private boolean canPullDown = true;
	private boolean canPullUp = true;
	private boolean enableHeader ;
	private boolean enableFooter;

	/**
	 * 执行自动回滚的handler
	 */
	Handler updateHandler = new Handler() {

		@Override
		public void handleMessage(Message msg) {
			// 回弹速度随下拉距离moveDeltaY增大而增大
			MOVE_SPEED = (float) (8 + 5 * Math.tan(Math.PI / 2
					/ getMeasuredHeight() * (pullDownY + Math.abs(pullUpY))));
			if (!isTouch) {
				// 正在刷新，且没有往上推的话则悬停，显示"正在刷新..."
				if (currState == REFRESHING && pullDownY <= refreshDist&&enableHeader) {
					pullDownY = refreshDist;
					refreshLoadTimer.cancel();
				} else if (currState == LOADING && -pullUpY <= loadMoreDist&&enableFooter) {
					pullUpY = -loadMoreDist;
					refreshLoadTimer.cancel();
				}

			}
			if (pullDownY > 0)
				pullDownY -= MOVE_SPEED;
			else if (pullUpY < 0)
				pullUpY += MOVE_SPEED;
			
			
			if (pullDownY < 0&&enableHeader) {
				// 已完成回弹
				pullDownY = 0;
				pullView.clearAnimation();
				// 隐藏下拉头时有可能还在刷新，只有当前状态不是正在刷新时才改变状态
				if (currState != REFRESHING && currState != LOADING)
					changeState(INIT);
				refreshLoadTimer.cancel();
			}
			if (pullUpY > 0&&enableFooter) {
				// 已完成回弹
				pullUpY = 0;
				pullUpView.clearAnimation();
				// 隐藏下拉头时有可能还在刷新，只有当前状态不是正在刷新时才改变状态
				if (currState != REFRESHING && currState != LOADING)
					changeState(INIT);
				refreshLoadTimer.cancel();
			}
			// 刷新布局,会自动调用onLayout
			requestLayout();
		}

	};

	public void setOnRefreshLoadListener(IPullToRefreshLoadListener listener) {
		mListener = listener;
	}
	
	public void setEnableHeader(boolean enableHeader){
		this.enableHeader=enableHeader;
	}
	
	public void setEnableFooter(boolean enableFooter){
		this.enableFooter=enableFooter;
	}

	public PullToRefreshLoadLayout(Context context) {
		super(context);
		initRefreshLoadVariables(context);
	}

	public PullToRefreshLoadLayout(Context context, AttributeSet attrs) {
		super(context, attrs);
		initRefreshLoadVariables(context);
	}

	public PullToRefreshLoadLayout(Context context, AttributeSet attrs, int defStyle) {
		super(context, attrs, defStyle);
		initRefreshLoadVariables(context);
	}

	private void initRefreshLoadVariables(Context context) {
		refreshLoadTimer = new RefreshLoadTimer(updateHandler);
		rotateAnimation = (RotateAnimation) AnimationUtils.loadAnimation(
				context, R.anim.refreshload_reverse);
		refreshingAnimation = (RotateAnimation) AnimationUtils.loadAnimation(
				context, R.anim.refreshload_rotating);
		// 添加匀速转动动画
		LinearInterpolator lir = new LinearInterpolator();
		rotateAnimation.setInterpolator(lir);
		refreshingAnimation.setInterpolator(lir);
	}

	private void scheduleTimer() {
		refreshLoadTimer.schedule(5);
	}

	/**
	 * 完成刷新操作，显示刷新结果。注意：刷新完成后一定要调用这个方法
	 */
	/**
	 * @param refreshResult
	 *            PullToRefreshLayout.SUCCEED代表成功，PullToRefreshLayout.FAIL代表失败
	 */
	public void refreshFinish() {
		refreshingView.clearAnimation();
		refreshingView.setVisibility(View.GONE);
//		switch (refreshResult) {
//		case SUCCEED:
			// 刷新成功
			refreshStateImageView.setVisibility(View.VISIBLE);
			refreshStateTextView.setText(R.string.refresh_succeed);
			refreshStateImageView
					.setBackgroundResource(R.drawable.ic_refreshload_succeed);
//			break;
//		case FAILED:
//		default:
//			// 刷新失败
//			refreshStateImageView.setVisibility(View.VISIBLE);
//			refreshStateTextView.setText(R.string.refresh_fail);
//			refreshStateImageView
//					.setBackgroundResource(R.drawable.ic_refreshload_failed);
//			break;
//		}
		// 刷新结果停留1秒
		new Handler() {
			@Override
			public void handleMessage(Message msg) {
				changeState(DONE);
				scheduleTimer();
			}
		}.sendEmptyMessageDelayed(0, 500);
	}

	/**
	 * 加载完毕，显示加载结果。注意：加载完成后一定要调用这个方法
	 * 
	 * @param refreshResult
	 *            PullToRefreshLayout.SUCCEED代表成功，PullToRefreshLayout.FAIL代表失败
	 */
	public void loadMoreFinish() {
		loadingView.clearAnimation();
		loadingView.setVisibility(View.GONE);
//		switch (refreshResult) {
//		case SUCCEED:
			// 加载成功
			loadStateImageView.setVisibility(View.VISIBLE);
			loadStateTextView.setText(R.string.load_succeed);
			loadStateImageView.setBackgroundResource(R.drawable.ic_refreshload_succeed);
//			break;
//		case FAILED:
//		default:
//			// 加载失败
//			loadStateImageView.setVisibility(View.VISIBLE);
//			loadStateTextView.setText(R.string.load_fail);
//			loadStateImageView.setBackgroundResource(R.drawable.ic_refreshload_failed);
//			break;
//		}
		// 刷新结果停留1秒
		new Handler() {
			@Override
			public void handleMessage(Message msg) {
				changeState(DONE);
				scheduleTimer();
			}
		}.sendEmptyMessageDelayed(0, 500);
	}

	private void changeState(int to) {
		currState = to;
		switch (currState) {
		case INIT:
			// 下拉布局初始状态
			refreshStateImageView.setVisibility(View.GONE);
			refreshStateTextView.setText(R.string.pull_to_refresh);
			// 上拉布局初始状态
			if (loadMoreView != null) {
				loadStateImageView.setVisibility(View.GONE);
				loadStateTextView.setText(R.string.pullup_to_load);
				pullView.clearAnimation();
				pullView.setVisibility(View.VISIBLE);
				pullUpView.clearAnimation();
				pullUpView.setVisibility(View.VISIBLE);
			}
			break;
		case RELEASE_TO_REFRESH:
			// 释放刷新状态
			refreshStateTextView.setText(R.string.release_to_refresh);
			pullView.startAnimation(rotateAnimation);
			break;
		case REFRESHING:
			Logger.log(this, "changeState", "REFRESHING",refreshStateTextView.getVisibility());
			// 正在刷新状态
			pullView.clearAnimation();
			refreshingView.setVisibility(View.VISIBLE);
			pullView.setVisibility(View.INVISIBLE);
			refreshStateTextView.setText(R.string.refreshing);
			refreshingView.startAnimation(refreshingAnimation);
			break;
		case RELEASE_TO_LOAD:
			// 释放加载状态
			loadStateTextView.setText(R.string.release_to_load);
			pullUpView.startAnimation(rotateAnimation);
			break;
		case LOADING:
			// 正在加载状态
			pullUpView.clearAnimation();
			loadingView.setVisibility(View.VISIBLE);
			pullUpView.setVisibility(View.INVISIBLE);
			loadingView.startAnimation(refreshingAnimation);
			loadStateTextView.setText(R.string.loading);
			break;
		case DONE:
			// 刷新或加载完毕，啥都不做
			break;
		}
	}

	/**
	 * 不限制上拉或下拉
	 */
	private void resetPullable() {
		canPullDown = true;
		canPullUp = true;
	}

	/*
	 * （非 Javadoc）由父控件决定是否分发事件，防止事件冲突
	 * 
	 * @see android.view.ViewGroup#dispatchTouchEvent(android.view.MotionEvent)
	 */
	@Override
	public boolean dispatchTouchEvent(MotionEvent ev) {
		switch (ev.getActionMasked()) {
		case MotionEvent.ACTION_DOWN:
			refreshLoadTimer.cancel();
			downY = ev.getY();
			lastY = downY;
			mEvents = 0;
			resetPullable();
			break;
		case MotionEvent.ACTION_POINTER_DOWN:
		case MotionEvent.ACTION_POINTER_UP:
			// 过滤多点触碰
			mEvents = -1;
			break;
		case MotionEvent.ACTION_MOVE:
			if (mEvents == 0) {
				if (pullDownY > 0
						|| (canPullDown()
								&& canPullDown 
								&& enableHeader 
								&& currState != LOADING)) {
					// 可以下拉，正在加载时不能下拉
					// 对实际滑动距离做缩小，造成用力拉的感觉
					pullDownY = pullDownY + (ev.getY() - lastY) / radio;
					if (pullDownY < 0) {
						pullDownY = 0;
						canPullDown = false;
						canPullUp = true;
					}
					if (pullDownY > getMeasuredHeight())
						pullDownY = getMeasuredHeight();
					if (currState == REFRESHING) {
						// 正在刷新的时候触摸移动
						isTouch = true;
					}
				} else if (pullUpY < 0
						|| (canPullUp()
								&& canPullUp 
								&& enableFooter 
								&& currState != REFRESHING)) {
					// 可以上拉，正在刷新时不能上拉
					pullUpY = pullUpY + (ev.getY() - lastY) / radio;
					if (pullUpY > 0) {
						pullUpY = 0;
						canPullDown = true;
						canPullUp = false;
					}
					if (pullUpY < -getMeasuredHeight())
						pullUpY = -getMeasuredHeight();
					if (currState == LOADING) {
						// 正在加载的时候触摸移动
						isTouch = true;
					}
				} else
					resetPullable();
			} else
				mEvents = 0;
			lastY = ev.getY();
			// 根据下拉距离改变比例
			radio = (float) (2 + 2 * Math.tan(Math.PI / 2 / getMeasuredHeight()
					* (pullDownY + Math.abs(pullUpY))));
			requestLayout();
			if (pullDownY > 0&&enableHeader) {
				if (pullDownY <= refreshDist
						&& (currState == RELEASE_TO_REFRESH || currState == DONE)) {
					// 如果下拉距离没达到刷新的距离且当前状态是释放刷新，改变状态为下拉刷新
					changeState(INIT);
				}
				if (pullDownY >= refreshDist && currState == INIT) {
					// 如果下拉距离达到刷新的距离且当前状态是初始状态刷新，改变状态为释放刷新
					changeState(RELEASE_TO_REFRESH);
				}
			} else if (pullUpY < 0 && enableFooter) {
				// 下面是判断上拉加载的，同上，注意pullUpY是负值
				if (-pullUpY <= loadMoreDist
						&& (currState == RELEASE_TO_LOAD || currState == DONE)) {
					changeState(INIT);
				}
				// 上拉操作
				if (-pullUpY >= loadMoreDist && currState == INIT) {
					changeState(RELEASE_TO_LOAD);
				}
			}
			// 因为刷新和加载操作不能同时进行，所以pullDownY和pullUpY不会同时不为0，因此这里用(pullDownY +
			// Math.abs(pullUpY))就可以不对当前状态作区分了
			if ((pullDownY + Math.abs(pullUpY)) > 8) {
				// 防止下拉过程中误触发长按事件和点击事件
				ev.setAction(MotionEvent.ACTION_CANCEL);
			}
			break;
		case MotionEvent.ACTION_UP:
			if (pullDownY > refreshDist || -pullUpY > loadMoreDist)
				// 正在刷新时往下拉（正在加载时往上拉），释放后下拉头（上拉头）不隐藏
				isTouch = false;
			if (currState == RELEASE_TO_REFRESH&&enableHeader) {
				changeState(REFRESHING);
				// 刷新操作
				if (mListener != null)
					mListener.onRefresh(this);
			} else if (currState == RELEASE_TO_LOAD&&enableFooter) {
				changeState(LOADING);
				// 加载操作
				if (mListener != null)
					mListener.onLoadMore(this);
			}
			scheduleTimer();
		default:
			break;
		}
		// 事件分发交给父类
		super.dispatchTouchEvent(ev);
		return true;
	}

	private void initRefreshLoadView() {
		// 初始化下拉布局
		pullView = refreshView.findViewById(R.id.iv_pullDown);
		refreshingView = refreshView.findViewById(R.id.iv_refreshing);
		refreshStateImageView = refreshView.findViewById(R.id.iv_refreshState);
		refreshStateTextView = (TextView) refreshView.findViewById(R.id.tv_refreshState);
		
		pullUpView = loadMoreView.findViewById(R.id.iv_pullUp);
		loadingView = loadMoreView.findViewById(R.id.iv_loading);
		loadStateImageView = loadMoreView.findViewById(R.id.iv_loadState);
		loadStateTextView = (TextView) loadMoreView.findViewById(R.id.tv_loadState);
		
		if (!enableHeader) {
			refreshView.setVisibility(View.GONE);
		}
		if (!enableFooter) {
			loadMoreView.setVisibility(View.GONE);
		}
	}

	@Override
	protected void onLayout(boolean changed, int l, int t, int r, int b) {
		if (!isLayout) {
			// 这里是第一次进来的时候做一些初始化
			refreshView = getChildAt(0);
			pullableView = getChildAt(1);
			loadMoreView = getChildAt(2);
			isLayout = true;
			initRefreshLoadView();
			refreshDist = ((ViewGroup) refreshView).getChildAt(0)
					.getMeasuredHeight();
			loadMoreDist = ((ViewGroup) loadMoreView).getChildAt(0)
					.getMeasuredHeight();
		}
		// 改变子控件的布局，这里直接用(pullDownY + pullUpY)作为偏移量，这样就可以不对当前状态作区分
		refreshView.layout(0,
				(int) (pullDownY + pullUpY) - refreshView.getMeasuredHeight(),
				refreshView.getMeasuredWidth(), (int) (pullDownY + pullUpY));
		pullableView.layout(0, (int) (pullDownY + pullUpY),
				pullableView.getMeasuredWidth(), (int) (pullDownY + pullUpY)
						+ pullableView.getMeasuredHeight());
		loadMoreView.layout(0,
				(int) (pullDownY + pullUpY)
						+ pullableView.getMeasuredHeight(),
				loadMoreView.getMeasuredWidth(),
				(int) (pullDownY + pullUpY)
						+ pullableView.getMeasuredHeight()
						+ loadMoreView.getMeasuredHeight());
	}
	
	/**
	 * 判断是否可以下拉，如果不需要下拉功能可以直接return false
	 * 
	 * @return true如果可以下拉否则返回false
	 */
	public boolean canPullDown() {
		Log.v("Logger", "canPullDown"+(pullableView instanceof AbsListView));
		if (pullableView instanceof AbsListView) {
			AbsListView absListView=(AbsListView) pullableView;
			if (absListView.getCount() == 0) {
				return true;
			} else if (absListView.getFirstVisiblePosition() == 0
					&& absListView.getChildAt(0).getTop() >= 0) 
			{
				return true;
			} else
				return false;
		}
		else if (pullableView instanceof WebView
				||pullableView instanceof ScrollView) {
			if (pullableView.getScrollY() == 0)
				return true;
			else
				return false;
		}
		else {
			return true;
		}
	}


	/**
	 * 判断是否可以上拉，如果不需要上拉功能可以直接return false
	 * 
	 * @return true如果可以上拉否则返回false
	 */
	public boolean canPullUp() {
		if (pullableView instanceof AbsListView) {
			AbsListView absListView=(AbsListView) pullableView;
			if (absListView.getCount() == 0) {
				// 没有item的时候也可以上拉加载
				return true;
			} else if (absListView.getLastVisiblePosition() == (absListView.getCount() - 1)) {
				// 滑到底部了
				if (absListView.getChildAt(absListView.getLastVisiblePosition() - absListView.getFirstVisiblePosition()) != null
						&& absListView.getChildAt(
								absListView.getLastVisiblePosition()
										- absListView.getFirstVisiblePosition()).getBottom() <= absListView.getMeasuredHeight())
					return true;
			}
			return false;
		}
		else if (pullableView instanceof WebView) {
			WebView webView=(WebView) pullableView;
			if (webView.getScrollY() >= webView.getContentHeight() * webView.getScale()
					- webView.getMeasuredHeight())
				return true;
			else
				return false;
		}
		else if (pullableView instanceof ScrollView) {
			ScrollView scrollView=(ScrollView) pullableView;
			if (scrollView.getScrollY() >= (scrollView.getChildAt(0).getHeight() - scrollView.getMeasuredHeight()))
				return true;
			else
				return false;
		}
		else {
			return true;
		}
	}

	class RefreshLoadTimer {
		private Timer timer;
		private Handler handler;
		private RefreshLoadTask loadTask;

		public RefreshLoadTimer(Handler handler) {
			this.handler = handler;
			timer = new Timer();
		}

		public void schedule(long period) {
			if (loadTask != null) {
				loadTask.cancel();
				loadTask = null;
			}
			loadTask = new RefreshLoadTask(handler);
			timer.schedule(loadTask, 0, period);
		}

		public void cancel() {
			if (loadTask != null) {
				loadTask.cancel();
				loadTask = null;
			}
		}

		class RefreshLoadTask extends TimerTask {
			private Handler handler;

			public RefreshLoadTask(Handler handler) {
				this.handler = handler;
			}

			@Override
			public void run() {
				handler.obtainMessage().sendToTarget();
			}
		}
	}

}